CLEVELAND -- A truck driver was indicted Tuesday on multiple counts of aggravated murder in the slayings of one person in 1997 and three people this year, and a county prosecutor called him a "serial killer."

Robert Rembert, who earlier served time in prison following a manslaughter conviction in another killing, was arrested last month after emerging from a shower at a truck stop outside Cleveland and has been held on a $1 million bond since, prosecutors said. There's an investigation into Rembert's "activities as an over-the-road truck driver," prosecutors said in a statement, which didn't provide additional details about it.

Rembert couldn't be contacted for comment while in custody Tuesday, and it was unclear if he had an attorney representing him.

Prosecutors say DNA evidence matched Rembert to the rape and strangulation deaths of Rena Mae Payne in May 1997 and Kimberly Hall this June. Rembert also is charged in the fatal shooting of Morgan Nietzel and his cousin Jerry Rembert at a Cleveland home on Sept. 20, the day before he was arrested.

Prosecutors say Robert Rembert lived in the home and shot Nietzel and his cousin in their heads. Nietzel's car was found in the parking lot of the truck stop in Medina County.

The fifth slaying was the fatal shooting of Dadren Lewis in December 1997. Rembert pleaded guilty to voluntary manslaughter and was sentenced in July 1998 to six years in prison.

Besides 10 counts of aggravated murder, Rembert also was indicted on charges of kidnapping, rape, aggravated robbery, grand theft and gross abuse of a corpse.